Most of the commercially available exercisers for jogging are of resistance-driven type, that is, a user must heavily tread a conveyor of the exerciser on tiptop to drive the same to move. Then, the user has to increase the exerciser's momentum by accelerating the movement of his or her tiptoes and thereby gets his or her legs exercised. Following disadvantages are found in the conventional jogger exercises:
1. The conventional jogger exercisers are usually unfoldable in their structure and therefore occupy considerably large room that adversely affects the convenient storage and transport of the exercisers. PA0 2. To use the resistance-driven jogger exerciser, the user must drive the exerciser to move by heavily treading on tiptoe on the conveyor of the exerciser and must tread the conveyor at an increasing speed to keep the exerciser moving. This is obviously an energy-consuming operation not easily performed by those younger or older users. PA0 3. The conventional jogger exerciser is designed for training the muscles of legs and can not be used to get the whole body exercised. PA0 4. Only the legs are moving when using such conventional jogger exerciser. The movement of treading is monotonous without enjoyment.